Season 4 of HBO’s Veep, which premieres Sunday, will be the White House comedy’s last with creator Armando Iannucci at the helm. HBO and the British writer-director announced his departure, citing the toll producing a series in the U.S. has taken on Iannucci and his London-based family. There has been no formal fifth-season pickup, but HBO has given a clear indication it is preparing for one by bringing a new showrunner to succeed Iannucci: former Curb Your Enthusiasm executive producer David Mandel.

“We have had conversations with Armando for some time about the challenges of maintaining his family life in London and producing a show in the states,” HBO said in a statement. “Armando is not replaceable, but we are confident that Veep will continue to be produced at the highest levels with new showrunner David Mandel.”

Both HBO and Veep star Julia Louis-Dreyfus have a history with Mandel, who landed his first primetime series writing gig on NBC’s Seinfeld and later served as executive producer on HBO’s Curb Your Enthusiasm, from Seinfeld co-creator Larry David, on which Louis-Dreyfus guest starred occasionally.

Iannucci posted this on Twitter today:

#VeepHBO returns Sunday. Our best season yet.Time for me to quit airports. I'm leaving on a high and kissing goodbye to jet-lag.

It is rare for a critically acclaimed series born from the singular vision of one person to lose its creator. It happened on another White House-set show, NBC’s The West Wing, with creator Aaron Sorkin stepping down, also after four seasons. The Emmy-winning drama continued for three more seasons with John Wells as showrunner.

Veep is HBO’s most acclaimed comedy series on the air, earning four Emmys to date, three for star Louis-Dreyfus.